What parts are swappable between chevy motors and oldsmobile motors?

What parts are swappable between chevy motors and oldsmobile motors i would like to know if i can use the exhuast manifold from an 85 buick regal on a 91 350 chevy motor.|||Chevrolet engine are by themselves, as well as Oldsmobile. that being said some Buick's used the Chev 305 v-8. because of the year differences they are not interchangeable|||It should work..Older Oldsmobiles and Chevys are a better fits..but the Cutlass, Monte Carlo, and Regal shared rhe same platform with a few tweaks here and there for a good 10 years...after 86 or 87...things kind of started to split apart...check out GM Performance parts..they make alot of universial parts.